= Solution
Three advantages of <integer arithmetic> for <raster graphics> are:
* \b[Cheap, fast operations.] Historically, <integer> addition, subtraction and shifts needed much less hardware and execution time than <floating-point arithmetic>, especially on machines without a <floating-point unit>. An incremental <Bresenham's line algorithm> needs only a few additions and a decision per <pixel>.
* \b[Exact decisions.] Provided <integer overflow> is excluded, the scaled <midpoint line decision> is exact. There is no accumulated <rounding error> that can move a decision across a half-<pixel> boundary; equality has a reproducible tie rule.
* \b[Simple storage and hardware.] <Integer> coordinates already identify <pixels>. An implementation can keep coordinates and decision variables in ordinary registers and use a small add/compare datapath, avoiding conversion between <floating-point numbers> and <integer> screen addresses.
These are historical and structural advantages, not a claim that every modern processor executes every <integer> operation faster. An <integer> implementation still needs sufficient width for its intermediate results. The compact answer is
$$
\boxed{\text{fast elementary operations; exact decisions; simple hardware and storage}.}
$$
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